ZIF‐8‐Derived ZnO and SnO 2 Form ZnO@SnO 2 Composites for Enhanced Photocatalysis under Visible Light

Abstract ZIF‐8 was used as a precursor and was converted to ZnO by calcining at high temperature to remove the organic functional groups therein. Then ZnO@SnO 2 composites were synthesized by hydrothermal method using ZnO as the carrier. All samples were characterized by XRD, SEM, EIS, Transient photocurrent test and Mott‐schottky test. The photodegradation effects of pristine ZnO, SnO 2 and ZnO@SnO 2 composites on tetracycline (TC) were evaluated and the best results were obtained (ZnO@SnO 2 =2 : 1), which could remove 91.2 % of TC under visible light irradiation. The effects of pH, ionic strength, and TC concentration were researched in batch experiments. ZnO@SnO 2 =2 : 1 showed favorable photocatalytic activity and stability, including pH and resistance to ionic strength. The enhanced photocatalytic activity of the ZnO@SnO 2 =2 : 1 composite could be ascribed to the lower recombination probability of electron‐hole pairs in the heterojunction and the enlarged surface area for TC adsorption during photodegradation. This study provided a reference for heterojunctions with excellent photocatalytic properties.